Having just recently FedExed a large package overseas, I am now wondering: how are cargo planes laoded? Clearly, you can’t just stuff packages in as you would a moving truck; weight limits and balance are fairly important in an airplane! Packages vary all over the place in size, weight and density. Do shippers use a piece of software to compute the most efficient packing schema? What does the inside of a large cargo plane, like a 747, look like, anyway? I assume that smaller packages are loaded into modular containers, and the containers are then placed in the plane as appropriate, but what about larger packages. My crate was almost 6 feet long and weighed over 300 pounds; where does something like that fit?
Yup, they use those big container modules.
Unless something is exceptionally heavy (or light) for its size, they just cram it in. I suspect your 300 pound crate, while heavy in its own self, is of an average density not terribly different than a similarly large stack of boxes. Also, as you said, they’re using 747s and other large aircraft. The precise location of a 300-pound item amid all that tonnage would be of negligible importance, so long as it’s on the correct plane and headed in the right direction.
Where they would need to pay attention in loading is the overnight letter envelopes. There’s essentially zero “dead” space in them, as opposed to say, a box 12 inches on a side containing something like a 6-ounce computer part and a lot of bubble wrap, so they’ve got a sizeable and predictable density.
There is also a good amount of software out there for “cubing out” such containers. You can enter any number of packages, with dimensions, weights, special circumstances, etc., tell it what kind of container you are filling, and the program will map out where to place each box to make the most out of the space. I have a demo of one called MaxLoadPro, which does all of the above … but I still can’t get it to help me balance the weight in a truck to send over the road. Still looking for suggestions…
Oh, and the inside of a 747? It’s just a huge empty space … note the rollers inthe floor for moving the containers.
Here’s a shot of the forward cargo area, and the ladder used to get into the cockpit.
IANA cargo loadmaster, but everything will be packed into standard cargo containers unless it is too large to fit or above the weight limit for the container. These will be weighed and then loaded in the right order to have the total load fit the plane’s gross weight limits and centre of gravity limits. Oversize and heavy cargo is loaded on pallets or other special handling methods, but is included in the weight calculations and load order.
Gross weight is often not a concern as the cargo frequently hits available space limits before weight limits. Centre of gravity (arranging things so the plane is not nose heavy or tail heavy) is VERY important.
Sometimes they’re not packed very well…